The appeal, due in October, follows a Court of First Instance judgment that awarded Li's ex-wife, Florence Tsang Chiu-wing, HK$1.2 billion in ancillary relief after the judge found she was entitled to maintain the lifestyle to which she had become accustomed.

In the judgment, handed down in December 2011, Mr Justice John Saunders wrote that the father and son had forged a loan agreement that transferred virtually all of Li's assets to his father and referred the matter for criminal investigation. The judgment has been under a publication embargo, but an executive summary was released to the media.

Filing the application yesterday, Lee's lawyers said the judgment was flawed and that allowing the appeal to be heard in open court would continue to infringe on his constitutional right to privacy and right to an impartial tribunal, which had been "blatantly" breached by the judge.

Michael Thomas SC, representing Lee, said Saunders was biased and had prejudged his client. He said the judge had also failed to warn the father and son that he was going to decide in the judgment that they had engaged in forgery, denying them the chance to mount any defence.

The ancillary relief hearing was heard in open court.

Kwan asked why the appeal should not be open to public scrutiny when there was a serious attack on the administration of justice. She said if the lower court had been wrong, Lee and his son would be vindicated by a Court of Appeal judgment.

Thomas said there should be a balance between the rights of his client and open justice, saying a public appeal could damage his client, even if the court ruled in his favour.

Lawyers for Tsang, whose eight-year marriage to Li ended in 2008, said she had the right to a public hearing, which was also in the public interest.

Charles Howard QC, for Tsang, said the embargo on the judgment should be lifted because the judge had dismissed an allegation made by the father that Tsang, who is a solicitor, had committed fraud.

He said it was not unusual for family court hearings to take place behind closed doors, and that even if judgments were not made public, appeals would still be heard in open court.

He also said Lee and Li had made fraud allegations in public, that the trial had been public, and that the executive summary was in the public domain, citing legal precedent that only in exceptional circumstances would an appeal be heard in private.

"It's in the interest of open justice that the judgment be published now," he said.

But Kwan said it would be inappropriate for her to make any order relating to release of the judgment, as it would pre-empt any made by the judges hearing the substantive appeal.